The 3/4" Apollo 4A series double check valves began production in 2008 and was discontinued in 2014. The 4A was replaced by the LF4A which is the lead free version. The body was constructed of bronze and check assemblies are self contained plastic modules. Check covers are threaded into the body. Check seats are replaceable. 4A and LF4A parts are interchangable. No special tools are required for servicing.

The 3/4" Apollo 4ALF series double check valves began production in 2013 and is still currently in production. The 4ALF replaced the original 4A series. The "LF" designates lead free and was introduced to meet low lead laws of 2014. The body is constructed of bronze and check assemblies are self contained plastic modules. Check covers are threaded into the body. Check seats are replaceable. 4A and 4ALF parts are interchangable. No special tools are required for servicing.